x1,y1,x2,y2=map(float,input().split())
print(f'{((x2-x1)**2+(y2-y1)**2)**0.5:.6f}') x1,y1,x2,y2=map(float,input().split()) x1 map(float,input().split()) map float input().split() ().split () input split y1 x2 y2 print(f'{((x2-x1)**2+(y2-y1)**2)**0.5:.6f}') print f'{((x2-x1)**2+(y2-y1)**2)**0.5:.6f}' y1,x2,y2=map(float,input().split()) map(float,input().split()) y1 x1,y1,x2,y2=map(float,input().split()) map(float,input().split()) x1 y2=map(float,input().split()) map(float,input().split()) y2 x2,y2=map(float,input().split()) map(float,input().split()) x2
x1,y1,x2,y2=map(float,input().split())
print(f'{((x2-x1)**2+(y2-y1)**2)**0.5:.6f}')
